Contemporary paintball guns or markers are equipped with solenoid-driven firing mechanisms that allow rapid firing of a number of projectiles with a single pull of the trigger. Paintballs have a soft-frangible envelope which can deform and even break under pressure. A deformation of the spherical shape of paintballs can lead to jamming in the feed port of the gun or only partial insertion into the breech. The firing of the gun with a paintball only partially inserted results in the chopping of the ball and fouling of the breech and barrel.
Mechanical as well as electronic anti-chop systems have been proposed in the prior art which simply allows firing of the gun only when a projectile is fully and properly inserted into the breech. Although such a system is effective in preventing the chopping of the paintball, it does not provide the user of the gun with an indication of whether a paintball is only partially inserted in the breech or if the paintball is jammed higher up in the feed port or in the paintball magazine. A jamming of the projectile ahead of the breech can often be corrected by dry-firing the gun in order to shake loose the jammed paintball. However, firing the gun on a partially inserted projectile can lead to a disabling of the weapon.